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Nov. 8, 1932. E. J. HAYMAN LOCKING sHEET METAL STRUCTURE i1/wanton 7/17/4 Filed MaICh 10, 1932 Patented Nov. 8, 1932 rasv :UNITED sr 'EBER J'. `HAYMAN, OF PABKERSBURG, .WEST VIRGINIA incassi LOCKING sanar MnrALasrRncrrmn Application filed March 10, .1932. :i Serial :No 597,925.-

My present invention Vrelates. to a. lock ,or latch for sheet metal structures and is. par vticularly applicable and useful for stovepipe sections. y 5 rlheprincipal object vof the .invention is to provide a pipe section with. a longitudinal lock or latch which will be adequately secure against accidental separation .but which Vmay be unlocked -or unlatched when :necessary without the Ause of tools and without mutilation of the section.

In flocking stovepipe sections heretofore placed on the marken-locks or :latches have been providedalo-ng adjacent longitudinal edges thereofeither at spaced apart intervals or substantially continuously alongthe entire edge. InV thelirst instance, due .to-thefact that the section was secured together only at spaced apart points, the general` public.` has more latches become unfastened, thev entire section might collapse. This sales resistance does not exist however to thosesections where they entire longitudinal edge constitutes a latch or lock. The difficulty with this latter type of pipe, however, is that once latched together, the edges cannot readily. be separated without the use of special tools, .or in the ab sence thereof, without springing or mutila-- tion of the folds constituting the'section .edge portion. Eventhou-gh Asuc-h latches are not capable of ready separation, theydoA permit a eertainameunt of un-desirable relative longitudinal Vmovement between the two edges locked together. This movement tends to throw thefsection or sections out of alignment.

Itis, therefere,;one of the objects 4of the fects.

To this end the invention contemplates in its broadest aspect a stovepipe section having a longitudinal locking .seam in which the tendency to separate is resisted at substantially every point along the seam in contradistinction to only a'few points as in the case of isolated or spaced apart latches. In addition, such latch as here contemplated is capable of ready separation when desirable, but incapable of any great amount of relative felt some hesitancy in being entirelysatisfed therewith, due to thefear that'shouldV one or p present'inventionto overcome the above de-` this invention.

preaching latchinglposition. v

longitudinal movement' of itstwo componentparts.. This, of course, .without the use. of extraneous fastening devicesrsuch as rivets, screws, bolts or the like.

.One form Aof the invention may consist of folding one longitudinal edge portion ofa sheet `upon itself to form three thicknesses of material, `the .last .foldhaving a portion projecting outwardly beyond the thus folded edge. Y An angular shoulder is formed in this projecting portion, spaced from the folded edge. With this female portion, the other or male 'edge .portion of the sheet co-operates. 'llhe latter .consists of two folds substantially at right angles to each other to form av locking shoulder and `ana-extension .projecting beyondthe ,-shoulder. VThis projection is adapted to bek received between two ofthe folds of the femaleportion so that thelocking .shouldersof yeach; part engage each otherand preventseparatio Y.

. Meansareprovided to: permit ready separation ,of the` locking parts when "desired which ,at the same time preventslundesirable .relative longitudinal movement therebe-. tween. Such means may consisty of a vboss y-on one of the complementaryparts,projecting through -or/into an opening in the other part. ,Asshowin the boss is provided with sloping `end portions which permits the two 8@ locking edges to ride up on each other wheny .force is exerted longitudinally but which will vmaintain the parts immovable longitudinally until ,.such force is deliberately applied. Having ridden uplon each other,l..85 the two lockingY edges maynow be readily separated bypulling them away fromeach other. 1 v The invention further consists in the novel combinatioin, construction' and arrangement of parts more fully hereinafter described and shown inthe `accompanying drawing. p

Fig. l is a view of a section according'to Fig. .2.is .an end viewof the section-of Fig. l.` l

.Fig..3-is Aa `sectional view alongthe line V3 3 of Fig. 1. n l

Fig. 4 islasectional view ofthe parts ap- 1% laterally extending portion'5,`the"portion lli" constituting a lockingshoulder, this .shoulder -being spaced slightlyfrom the folded' edge 7 of the part A. Itis to be noted that the locking shoulder 4L extends substantially the entire length of the section.

The male part B is folded twice, each fold being substantially at right angles to each other to form the part 8 and the extension 9, the former constituting av locking shoulder Vadapted to engage the locking shoulder 4C Y when the parts A and B aremated and inter` looked. rIhe fact that the shoulder 4- is spaced slightly from the folded edge 7, permits the extension 9nto be readily inserted therebetween when the section is to be latched together.

From the above, it will be apparent that when once snapped together, it is extremely difficult for the parts A and B to be completely separated from each other without either lifting up the folds 1 and 2 to clear the junc' ture of folds 8 and 9, or to depress the fold 5 to clear the parts 8 and 9. Ineither event, the latch must be unduly distorted and mutilated. For this reason, means are provided to-permit separation of the parts when desired. It is also to be noted that with only the mechanism above described, the parts A and BV mayslide longitudinally a considerable distance relative to each other and that such movement would throw the entire section out of alignment. This undesirable movement is prevented by the same instruvmentality which permits separation of the parts, and comprises the following. j

In the modification shown in the drawing, the extension 9 in part B is provided with an offset boss 10 which when the parts are inV full latched position, projects toward the axis of the pipe andinto a corresponding" opening 11 in part A. Obviously this opening may be either-.an actual space or slot cut n or punched outof the part A or an offset 12 may be provided as shown in Figs. 6 and 7 In either event, the boss 10 is provided with sloping end shoulders 13 so that when theY two edge portions A and B, are forced to move longitudinally, the boss 10.will ride under the innermost f old 3 and separate the folds 3 and 2 to such an extent that the parts A and B may then be withdrawn from locking engagement. However, as the boss 10 increases in height toward the extreme edge of the fold or extension 9 to an appreciable extent, it requires deliberately applied force to cause this extent of movement. As a result, the boss and its complementary recess Vprevent any tendency toward accidental relative longitudinal movement. vBy extending the slot or offset beyond the shoulder in the p part B, a gap-or openinOn 14 is provided which facilitates entering ofthe boss into the part A when the complementary edges of the section are mated.

VIclaim:

l. A locking stovepipe section having two mating edge portions, one edge being folded upon itself to form three thicknesses of material,rtwo of which are4 on the inside of the pipe, thel innermost fold having a portion yextending outwardly toward the periphery of the pipe to form alongitudinal locking shoulder spaced from the adjacent folded edge of the two outside folds, the innermost fold havingk a recess therein, the other mating edge portion having a; complementary longitudinal locking shoulder and an extension beyond the shoulder, with a boss on said extension, the two locking shoulders being adaptedto engage each other Vand the boss being adapted to project into the recess when the said shoulder extension is located between the said innermost and intermediate folds.

f2. Y The device of claim 1 in which the boss` is provided with sloping end portions; Y

3. The device of claim 1 in whichthe recess comprises aslot.

' l. 'Ihe device of claim 1 in `which the height of the boss is greater than the normal distance between the intermediate and innermost folds. A

5. The device of claim 1 in which the height of the bossincreases in a direction toward the extreme edge of the shoulder exa.

tension.

6. The device of claim 1 in which the recess comprises a portion offset from the plane ,of the innermost fold.

.7. rlhe device of claim 1 inwhich the re-,g

cess constitutes an offset portion similar to' but of-larger proportions than the boss. y,

In testimony whereof, I have hereunto subscribed myiiame this 2nd day of March, 1932.

EBER AJ. I-IAYMAN. 

